Engineering students provide concrete plans for Red Bridge

Since early 2017, Colfax's Quarry Springs Park has been hoping to acquire the historic Red Bridge, listed on both the National Registry of Historic Places and Preservation Iowa's Most Endangered Properties program, from its original location in Reasnor. In the early 20th century, Red Bridge sat on the main artery connecting Newton, Monroe and Pella before the construction of Highway 14.

Today, the bridge is but a shadow of its original design. Planks have fallen from its deck and flooding in July threatened to wash the bridge away entirely. Joe Otto, a Colfax native and historian, spearheaded the movement to save this architectural treasure. Originally, Otto estimated approximately $370,000 to uproot, move, install and restore the bridge in Quarry Springs Park.

Otto began applying for grants last spring to help fund relocation. The application for the Emergency Historical Resource Development grant lacked signatures from the Army Corps of Engineers and the Department of Natural Resources and didn't provide a concrete plan for the bridge's relocation and rehabilitation. Without those necessary elements, the State Historical Society of Iowa had to deny the request.

Supporters of the Red Bridge turned to civil engineering students at the UI to help them solidify their plans for relocation. As part of their degree requirement, all University of Iowa civil engineering students must complete a capstone project, and Alexandre Rohrbach, Adam Tuchsherer and Bryton Meyer chose to assess, plan and estimate the cost of the Red Bridge’s relocation. On Dec. 12, the three students shared their findings during a special presentation before the Quarry Springs Park regular board meeting.

“Right now, it’s all conceptual,” Kim Seebeck, president of the Quarry Springs Park board, said. “We don’t have any funding. We’re going to develop the project, and they’re here to give us the low-down.”

The UI students began their project by examining Quarry Springs Parks’ master plan. Although the master plan places Red Bridge across the South Skunk River at a crossing parallel to that of the bridge over Highway 117 — thereby connecting the park to downtown Colfax with a pedestrian trail — the students believe suspending the bridge over the lake between the Schlosser Trust land and the southern edge of Quarry Springs is more feasible.

“This alternative location did not require hydraulic analysis that would be necessary for suspending the bridge over the river,” Tuchsherer said. “This location also requires a less-complex foundation for the bridge. For the bridge to sit over the river, you need to add more piers and abutments and also beef them up to make them resist the flow of the water, especially when you have debris hitting the concrete.”

Installing and restoring the Red Bridge will require excavation and fill along the banks where they plan to anchor it. The fill will shorten the distance between the banks and eliminate the need to use the pony trusses currently extending the bridge’s reach across the South Skunk near Reasnor and ensure the bridge sits 8 feet above the river according to the students’ evaluation of 50-year floods. To transform the bridge into a functional passage, the students recommend replacing the deck, using pre-fabricated stainless steel cables for railings, adding a rub-rail for cyclists and illuminating the structure with LED floodlights.

Although weather conditions prevented the students from visiting Red Bridge, its age compels them to suspect lead-based paint currently coats the structure.

“With that assumption, the Red Bridge is going to need to be sandblasted and painted,” Meyer said. “The sandblasting and painting can take place after the Red Bridge gets placed on its new abutments; however, Hawkeye engineering recommends the structure be sandblasted and painted at a local facility during the transportation process.

The students estimate the cost of bridge transport at $201,500, the cost of constructing abutments at $423,925, and the cost of refurbishing the bridge at $127,050. Thus, acquiring and improving the bridge alone will cost $752,475.

One of Quarry Springs Parks’ main goals in obtaining Red Bridge was to provide pedestrian access from downtown Colfax to the park. Although situating Red Bridge in the alternate location, instead of suspending it across the South Skunk River, will not provide this access, the students designed an alternate pedestrian trail.

“We had an extra scope to our project,” Rohrbach said. “We’ll increase the Highway 117 bridge sidewalk.”

The expansion of the existing sidewalk on the Highway 117 bridge will increase sidewalk width from 5 to 10 feet. The students suggested extending the pier supporting the current sidewalk by wedging plates around a steel insert and drilling them through the concrete.

The sidewalk expansion on Highway 117 over the river would connect to an improved sidewalk system extending from the old Monroe Table Company in downtown Colfax. The students suggest bumping out the existing curbs to create an eight-feet wide, 6-inch thick concrete sidewalk leading to the bridge on Highway 117. The sidewalk and Highway 117 bridge will then link to a 1.3 mile trail improvement within the park.

The students have estimated the cost of the bridge expansion at $621,255, the cost of the sidewalk improvement at $231,840 and the cost of the trail improvement at $517,850. These adaptations, combined with the cost of bridge relocation and rehabilitation at $752,475, comprise the first phase of the project for a total of $2.105 million.

In addition to the relocation, renovation and installation of the bridge and the improved sidewalk and trail system, the engineering students recommend installing another 7.5 miles of trails to connect the bridge and sidewalks. Creating this 7.5 mile stretch would involve tree removal, excavation and fill, plastic netting to prevent erosion during construction and paving. The engineering students anticipate this project would cost the park $3.792 million. Incorporating the second phase of trail construction would raise the cost of the entire project nearly $5.9 million.

Although these plans add several layers to Otto’s original speculations, the engineering students from the University of Iowa have not yet graduated and therefore, are not yet licensed.

“It would need to be further evaluated by a professional engineer,” Meyer reminded the crowd Dec. 12.

Despite the need for inspection by a licensed professional, Jeff Davidson, Jasper County’s Hometown Pride Community Coach, believes including these concrete plans and cost estimates will aid Quarry Springs Park in grant applications.